in which case this is an ntl problem and nothing to do with your pc...
ip's which range from .248 - .253 are pre-registration
anything outside this range is a registered ip address
turn the modem off the pc off and both back on
if you are still picking up an ip address in this range contact technical support
a) ask them to check you mac address on the system is correct
b) get them to check you are registered to the correct dhcp
c) if above 2 correct ask them to remove and re-add the cable modem back on
this should solve the problem for you
no amount of working on the pc is going to do anything for you
you can prove your pc is ok by going to
https://autoreg.autoregister.net ... bet it displays for you
